Automatic firearm construction

ABSTRACT

An automatic firearm, particularly a gas operated weapon, comprises a cartridge feeding system which operates upon movement of a reciprocating breech block to feed a series of cartridges in succession to the cartridge chamber of the gun barrel under the control of gas pressure which is generated during the firing of each cartridge. A cartridge feeding device for the gun includes a multi-operable cartridge magazine which has a plurality of rotatable stars arranged at transversely spaced locations and which may be shifted selectively into operative positions in which a rotatable shaft portion becomes automatically coupled to a coupling and indexing mechanism which is carried on the gun. The coupling and indexing mechanism comprises a rotary portion which is rotated upon movement of a piston member which is connected during the firing to the pressure gases so that it is shifted to effect rotation of the coupling. The coupling is connected to the shaft of the indexing star which is in the operative position so that the cartridges of this portion are fed in succession to the cartridge chamber of the gun barrel. The construction permits shifting from one rotatable cartridge supplying star system to another or to a system in which the cartridges are fed either by the rotatable star or by a magazine clip which feeds the cartridges directly downwardly to a position in which they are moved to the cartridge chamber.

United States Patent 1 in] 3,875,845

Hupp et al. Apr. 8, 1975 AUTOMATIC FIREARM CONSTRUCTION weapon,comprises a cartridge feeding system which [75] Inventors: GerhardtHupp,Obcrndorf. Neckar; gr i s? l g l re clprocatm g ifi Helmut Mad".schmmbergi both uf 0c 0 cc a series 0 car r1 ges lfl succession 0 eGerman cartridge chamber of the gun barrel under the control of gaspressure which is generated during the firing of [73] Assignec'.lndustrier e each cartridge. A cartridge feeding device for the gunKarlsruhe-Augsburg AG. Karlsruhc. includes a multi-operable cartridgemagazine which Germany has a plurality of rotatable stars arranged attrans- [22] Filed: Jan. 4 I974 versely spaced locations and which may beshifted selectively into operative positions in which a rotatable l l PPN06 430-603 shaft portion becomes automatically coupled to a couplingand indexing mechanism which is carried on the [30] Foreign ApplicationPriority Data gun. The coupling and indexing mechanism comprises J 7 G II q q a rotary portion which is rotated upon movement of a l9 ermm) 3piston member which is connected during the firing to the pressure gasesso that it is shifted to effect rotation 89/33 ga 3 of the coupling. Thecoupling is connected to the shaft l of the indexing star which is inthe operative position held or seanh 89/33 33 gg lj so that thecartridges of this portion are fed in succession to the cartridgechamber of the gun barrel. The

References Cited construction perm|ts shifting from one rota a e carFORElGN PATENTS OR APPLICATIONS 1206.025 9/l97t) United Kingdom 89/33 BCPrimary E.\'uminerStephen Ct Bentley Attorney, Agent, or FirmMcGlew andTuttle [57] ABSTRACT An automatic firearm, particularly a gas operatedtridge supplying star system to another or to a system in which thecartridges are fed either by the rotatable star or by a magazine clipwhich feeds the cartridges directly downwardly to a position in whichthey are moved to the cartridge chamber.

6 Claims, 5 Drawing Figures PATENIEDAPR saws SuLU 1 UP 5 AUTOMATICFIREARM CONSTRUCTION FIELD AND BACKGROUND OF THE INVENTION Thisinvention relates in general to the construction of firearms and. inparticular. to a new and useful firearm which includes a cartridgefeeding system which includes at least two rotatable star feedingmechanisms for separately feeding cartridges. for example. from acontinuous belt and which may be selectively positioned in an operativeposition in which they become coupled to the indexing mechanism of thegun for feeding the cartridges to the cartridge chamber for firing.

DESCRIPTION OF THE PRIOR ART In action. particularly with heavyrapid-fire weapons. such as automatic 2() to 30 mm guns for explosiveprojectiles having a high initial velocity. it is frequently necessaryto attack in immediate succession living targets with highly explosiveshells and armored targets with armor piercing shells. To effect thisammunition change in conventional weapons. the entire cartridge beltmust be removed in a complicated and time consuming manner and replacedby another with the desired ammunition.

To remedy this shortcoming. devices are known which permit feeding ofone sort of cartridge by means of belts and another by means ofattachable magazines. Such devices. however. have a limited storingcapacity for the second sort of ammunition. for example. armorpiercingammunition.

There is further known a weapon (Stoner) which is equipped with twoseparate feeding mechanisms mounted on the left and right-hand sides andadapted to introduce belts with different sorts of ammunition.

for example. cartridges with explosive projectiles and cartridges witharmor-piercing projectiles. In this construction. both feedingmechanisms are mounted on a common base. which is pivotable in respectto the weapon housing to such an extent that the forwarding breech blockseizes either cartridges coming from the left. for example. witharmonpiercing projectiles. or cartridges coming from the right withexplosive shells. Even though. in this case. a selective firing of twodifferent sorts of ammunition is possible without changing the belt. theconstruction is too expensive and complicated. Another drawback of thisconstruction is that the second sort of ammunition. contrary to theintended tactical purpose. does not become effective immediately afterthe switching over of the cartridge feeding mechanism because onecartridge of the other sort of ammunition is fed in before the switchingis still in the barrel and must be fired first. In action. this ishighly undesirable. if only because thereby. for example. when usingtracer ammunition or the like. one s own emplacement or location may bebetrayed to the enemy.

The present invention is directed to the problem of eliminating suchdrawbacks and disadvantages of the known weapons and of providing acartridge feeding device permitting the switching over from one sort ofammunition to another within a minimum of time and with relatively smallforces and assures that after the switching operation. the followingfirst shot is done with the desired or required other ammunition.

SUMMARY OF THE INVENTION In accordance with the present invention. thisproblem is solved substantially by providing a cartridge feeding devicecomprising two parts of approximately identical mirror opposite designserving to receive different sorts of ammunition and positioned parallelto the longitudinal axis of the weapon. the switching over from one sortof ammunition to the other being effected by shifting the devicetransversely to the longitudinal axis of the weapon. whereby. with theaid of a mechanism associated thereto. the device is automaticallycoupled to. or uncoupled from. a mechanism which is mounted in front ofthe cartridge feeding de vice in the direction of the muzzle and which.under the action of the gas pressure supplied thereto during thebackward motion of the breech block and while coupled to the respectiveselected part of the cartridge feeding device. effects the transfer ofthe cartridge received in the feeding belt into the cartridge chamber ofthe weapon.

According to a development of the invention idea. the mechanism mountedin front of the cartridge feeding device in the direction of the muzzleincludes a piston subjected to gas pressure and comprising a rackportion or the like permanently meshing with a pinion. To assure theoperation of the mechanism in accordance with the invention and therebythe switching from one sort of ammunition to the other. the pinionmeshing with the rack is permanently in gear with a second pinion. Bothof the pinions in mesh with each other are provided with simple couplingmeans which are highly reliable in operation and each serve to becoupled to. or uncoupled from. a selected one ofasially movable andconformably designed shafts forming a part of the cartridge feedingdevice. The coupling means on the pinions comprise T-shaped grooves withwhich the conformably designed shafts may be engaged or from which theymay be disengaged by shifting. in order to change the sort ofammunition.

By an appropriate application of the main idea of the invention. thepossibility is given. of course. to provide a firing of more than twodifferent sorts of ammunition in the same simple manner. This can beachieved. in accordance with the invention. by providing a bar-typemagazine or the like mounted between the approximately reflex-designedhalves of the cartridge feeding device.

The present invention offers many advantages which cannot bedisregarded:

The switching over from one sort of ammunition to another is carried outwith relatively simple but highly effective and rugged means. This is anindispensable condition for assuring the operation of the weapon inaction. even under extremely difficult circumstances.

Aside from the fact that by using the inventive arrangement it is easilypossible to provide for the firing of even a third sort of ammunition.the feeding of the cartridge belt is independent of the breech block andeffected by the gas pressure acting on a special piston which. forspace-saving and other similar reasons. is also in the form of a rack.

The highly space saving and narrow construction of the cartridge feedingdevice. in accordance with the invention. is of particular importance.This is possible due to the arrangement whereby the cartridge to beintroduced into the cartridge chamber is delivered to an offset positionrelative to the longitudinal axis of the weapon. Not less important isthe advantage that after the switching over from one sort of ammunitionto the other, the very next fired cartridge is already of the se lectednew sort of ammunition.

Accordingly. it is an object of the invention to provide a firearmconstruction which includes a coupling and indexing mechanism which isoperated upon the firing of each cartridge and which has a rotatablecoupling part which is selectively coupled to one of a plurality ofseparate cartridge feeding stars or indexing mechanisms of a cartridgefeeding system which includes two or more transversely orientedcartridge feeding systems which may be selectively placed in anoperative position.

A further object of the invention is to provide a weapon which is simplein design. rugged in construction and economical to manufacture.

For an understanding of the principles of the invention. reference ismade to the following description of typical embodiments thereof asillustrated in the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS In the Drawings:

FIG. I is a partial vertical sectional view of a firearm ha\ ing acartridge feeding device constructed in accor dance with the invention:

FIG. 2 is a top view of the firearm shown in FIG. 1; FIG. 3 is a sectiontaken along the line [3-8 of FIG. I;

FIG. 2'. and

FIG. is a view similar to FIG. 4 of another embodiment of the invention.

GENERAL DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to thedrawings in particular. the invention embodied therein in FIGS. 1 to 4.comprises a firearm having a barrel 50 with a bore axis 1.

In accordance with the invention, the weapon is pro vided with acartridge feeding device. generally designated 2, which as bestindicated in FIG. 4 contains two separately operable cartridge feedingmechanisms or cartridge feeding stars 4 and 4 which are adapted to beconnected through a coupling and indexing mechanism. generallydesignated 8, to provide for a selective feeding of cartridges from acontinuous supply or belt or a continuous supply or belt 15'.

As shown in FIG. 1. the feeding device 2 is constructed to receive andfeed a series of cartridges 3 by the rotation of a feeding star 4 into acartridge chamber 5. The cartridge feeding mechanism 2 is held in position over the rifle barrel 50 by a bolt 6 which is hinged to an eye 21!of the cartridge feeding device 2 and engages into a stationary eye 7which is mounted on the combination coupling and indexing device 8.Suitable means on the eye 7 are provided for clamping the bolt 6 in afixed axial position.

In accordance with a feature of the invention. the operating starmechanism 4 and the operating star mechanism 4' each include an axiallymovable shaft 2b which has a coupling part or T-shaped coupling portionat its end which is adapted to be coupled selectively to the couplingand indexing means 8 in accordance with which ofthe feeding stars 4 or4' is to operable. For this purpose. the coupling and indexing mechanism8 includes coupling elements 80 and 8b which are under the biasinginfluence ofa torsion spring 9 to urge them 4 is a section taken alongthe line CC of FIG.

into a position in which they are engageable with the couplings 8a or812 of the shaft 2b or 2b of the respective star mechanism 4 and 4'. Thecoupling means and the spring 9 are mounted in bushings 8c and 8d andthe outer circumferences of the bushings 8c and 8a are provided withteeth 8e and 8f. respectively. so that they form pinions which areengageable with a piston rack member II, as shown in FIG. 3. Thecoupling and indexing mechanism 8 is fixed to the top of the stock 52 ofthe weapon so that it overlies the barrel 50 in the vicinity of thecartridge chamber 5. The cartridge feeding device 2 is shift-abletransversely to the longitudinal axis of the weapon as indicated by thedouble arrow in FIG. 2. A guide pin 10 is mounted in the eyes 2aarranged at each end of the feeding device and it is slidably guided ina sleeve 8;; which is affixed to the coupling mechanism 8. The slidingmotion takes place when the cartridge feeding device 2 is shiftedtransversely in order to change from one type of ammunition to another.

The coupling and indexing mechanism 8 includes a piston 11 which isslidable in a housing portion 8a of the coupling and indexing mechanismtransverse to the main axis or bore axis 1. The piston 11 is shaped as arack Ila and this rack portion meshes with the teeth of a pinion 8ewhich is also in meshing engagement with a pinion 8f. The pinion 8e andSfare provided with coupling parts 8a and 8b which engage with theT-shaped coupling parts 2(' of the shaft 2b or 211'.

During operation of the weapon a breech block. which is not shown. movesbackwardly after the firing of each cartridge. The firing of thecartridge produces a pressurization ofthe cylinder 8/: containing thepiston 11 due to flow of the gases through passages 12, I3 and 14, sothat the piston 11 moves to the right. as indicated in FIG. 3. Thisshifting of the piston 11 produces a rotary movement of a coupling partthrough the pinions 8c and 8f so that the shaft 211 which is coupledthereto is rotated also. This rotation of the shaft 2b provides arotation of the feeding star 4 so that the cartridges 3 which arecontained in a belt 15 are advanced to a position in which they aredeposited into the barrel chamber S. In the position of the cartridgefeeding device 2 shown in FIG. 4. the belt 15 is in an operatingposition in which it is being moved by the star 4. When the cartridgetype is to be changed. the cartridge feeding mechanism 2 is shifted tothe left or the dotted line position shown so that the star 4' is movedinto an operative position. The cartridge 3, which is transported by thefeeding star 4, shown in the solid position of FIG. 4, is mo\ eddownwardly in the direction of the black arrow 54 until it is positionedclose to the inlet opening leading to the cartridge chamber 5, as shownin FIGv 1. In order to obtain the smallest possible shifting distance ofthe cartridge feeding device 2, the central axis of the feeding star inthe final or operative position is located laterally offset with respectto the central axis of the weapon and by an amount equal to the distancey. Thus. the delivery of the cartridge 3 into the cartridge chamber 5takes place in a position within the feeding star 4 corresponding to anangular deviation by the amount of the angle or shown in FIG. 4.Consequently, if the axis-to-axis distance of the two feeding stars 4 in.t, as shown in FIG. 4, the transverse shifting distance of thecartridge feeding device is a distance equal to minus the distance 2y.The cartridge 3 to be introduced into the cartridge chamber 5, as shownin FIG. 1, per- 5 forms because of its offset position by the angle a alateral and simultaneously downward movement. By such an arrangement. itis possible to shorten the distance in which the feeding mechanism 2need be shifted and. in addition. this shortens the time required for achangeover from one type of ammunition to another.

While the belt is being fed in the direction of the arrow 54 into thecartridge chamber. the empty belt is moved off in a direction of thewhite arrow 56. The angle B indicates the possible range in which thebelt 15 may be removed either in a direction directly upwardly or in adirection substantially horizontally.

When the center line of the Cartridge feeding device 2 is verticallyaligned with the central axis of the weapon. the position of the deviceis a neutral position and the cartridges 3 cannot be delivered into thecar tridge chamber 5 either from the left or from the righthand side. Inconsequence. this intermediate neutral position of the cartridge feedingdevice 2 provides an additional safety measure in respect to the use ofthe weapon.

The construction and operation of the cartridge feeding mechanismindicated in FIG. 5, and generally designated 2'. is substantially thesame as that shown in FIG. 4 but in addition to the two feeding stars 40and 41:, there is provided a bar-type magazine feed 16 which is mountedbetween housings ofthe stars 4a and 4a. Ammunition l7 placed in themagazine 16 may be. for example. a type of ammunition referred to asindicator ammunition, and this may be used selectively between thefiring of one magazine portion or the other for purposes of marking atarget.

While specific embodiments of the invention have been shown anddescribed in detail to illustrate the application ofthe principles ofthe invention. it will be understood that the invention may be embodiedotherwise without departing from such principles.

What is claimed is:

1. An automatic firearm. particularly a gas-operated firearm having areciprocating breech block and a cartridge feeding device which iscontrolled by the gas pressure during the firing ofa cartridge to feed aseries of cartridges in succession to the cartridge chamber of a gunbarrel. comprising a coupling and indexing mechanism including a membershiftable by gas pressure generated by the firing of a cartridge and arotatable coupling part connected to said member and rotated thereby. acartridge feeding device including a transversely movable housing withfirst and second transversely spaced rotatable cartridge feeding starswhich are rotatable to feed cartridges in succession to the bar relcartridge chamber. said cartridge feeding device being shiftable toalign a respective one of said first and second stars in operativepositions in respect to said rotatable coupling and the cartridgechamber. said stars being selectively and alternatively alignable in anoper ative position and each star having a shaft with a coupling portionwhich is separately engageable with said rotatable coupling when in anoperative position whereby to connect the associated star so as to feedthe ammunition to the cartridge chamber.

2. An automatic firearm. according to claim I. wherein said coupling andindexing mechanism in cludes a cylinder. said member comprising a pistonshift-able in said cylinder. means for connecting gas pressure generatedin the gun barrel cartridge chamber during the firing of a cartridge tosaid cylinder to displace said piston. said piston being connected torotate said rotatable coupling.

3. An automatic firearm. according to claim 2. wherein said pistonincludes a rack portion. said rotat able coupling part comprising apinion in meshing engagement with said rack portion.

4. An automatic firearm. according to claim 3. wherein each of saidfirst and second rotatable stars includes a central rotatable shafthaving a shaft coupling formation at its end. said shaft couplingformation being engageable with said rotatable coupling. said rotatablecoupling comprising first and second rotatable gears engageable withsaid rack.

5. An automatic firearm. according to claim 1, wherein said rotatablestars each include a shaft coupling part having a T-shape groove.

6. An automatic firearm. according to claim 1. including a bar-typemagazine located between said rotatable stars for receiving a third typeof ammunition and having a downwardly feeding discharge for thecartridges located between said first and second stars.

=i t i

1. An automatic firearm, particularly a gas-operated firearm having areciprocating breech block and a cartridge feeding device which iscontrolled by the gas pressure during the firing of a cartridge to feeda series of cartridges in succession to the cartridge chamber of a gunbarrel, comprising a coupling and indexing mechanism including a membershiftable by gas pressure generated by the firing of a cartridge and arotatable coupling part connected to said member and rotated thereby, acartridge feeding device including a transversely movable housing withfirst and second transversely spaced rotatable cartridge feeding starswhich are rotatable to feed cartridges in succession to the barrelcartridge chamber, said cartridge feeding device being shiftable toalign a respective one of said first and second stars in operativepositions in respect to said rotatable coupling and the cartridgechamber, said stars being selectively and alternatively alignable in anoperative position and each star having a shaft with a coupling portionwhich is separately engageable with said rotatable coupling when in anoperative position whereby to connect the associated star so as to feedthe ammunition to the cartridge chamber.
 2. An automatic firearm,according to claim 1, wherein said coupling and indexing mechanismincludes a cylinder, said member comprising a piston shiftable in saidcylinder, means for connecting gas pressure generated in the gun barrelcartridge chamber during the firing of a cartridge to said cylinder todisplace said piston, said piston being connected to rotate saidrotatable coupling.
 3. An automatic firearm, according to claim 2,wherein said piston includes a rack portion, said rotatable couplingpart comprising a pinion in meshing engagement with said rack portion.4. An automatic firearm, according to claim 3, wherein each of saidfirst and second rotatable stars includes a central rotatable shafthaving a shaft coupling formation at its end, said shaft couplingformation being engageable with said rotatable coupling, said rotatablecoupling comprising first and second rotatable gears engageable withsaid rack.
 5. An automatic firearm, according to claim 1, wherein saidrotatable stars each include a shaft coupling part having a T-shapegroove.
 6. An automatic firearm, according to claim 1, including abar-type magazine located between said rotatable stars for receiving athird type of ammunition and having a downwardly feeding discharge forthe cartridges located between said first and second stars.